The black walnut is an Ontario native, prized for its timber as well as for nuts. Large 150 year old specimen trees have been sold for veneer for thousands of dollars. It is important to get assistance from the Ministry of Natural Resources when considering the sale of valuable trees. Black walnut timber plantations are routinely established in the fertile Southern Ontario lowlands.

The black walnut is one of the most successful edible nut trees in Ontario. It is well adapted to our winter cold, and unlike Persian walnuts, avoids late spring frosts by delaying leafing in the spring. As a result it is suited to much of Southern Ontario. Plantings and wild trees can be found from Windsor in the south-west to Ottawa in the east. There are even black walnut trees thriving in Quebec City east of that. A strain of black walnut has even adapted itself to the rigors of the dry fertile prairies (zone 3) of Manitoba.

More limiting than climate is the soil type and drainage conditions. Black walnut succeeds well beyond its native range, wherever pH readings are between 6 and 7. Eroded limestone soils ranging from sand to clay are ideal. They are at home along the whole length of the eroded edge of the Bruce Trail (Niagara escarpment to the Bruce Peninsula). Deep well-drained soils are important to proper development and growth.

28 year old "Emma K" Black Walnut

Though the black walnut is well established in Ontario, the crop of delicious nuts it produces has not been utilized except by a few persistent foragers. The early pioneers highly valued the rich tasting nuts and put away many sacks of them each year. Each farmstead had its orchard of fruit and nut trees to provide it with its source of winter food. That all but disappeared when easier cracking Persian walnuts became common in the grocery stores. With modern tree shakers, harvesters, nut hullers, crackers and sorting machines being available, it is possible to profit from the nut crop again. The industry is alive and well in Stockton, Missouri where millions of pounds of black walnuts are processed each year. The total kernel crop is marketed domestically. Almost none is left over for export.

Though the black walnut industry is based on wild trees in North America, many selections have been found that offer larger nut meats in easier cracking shells. A few of the cultivars that do well in Southern Ontario include: Emma K, Thomas, Weschcke and Bicentennial.